The goal of this paper is to examine the potential of micro-algae
as renewable bio-energy source by assessing two key parameters:
the energy consumption ratio and overall costs of bio-energy production.
This paper focuses only on photo-autotrophic micro-algae,
which utilise sunlight during micro-algae growth. Raceway ponds
and horizontal tubular systems are analysed in detail by modelling
annual productivity, determining energy consumption ratios and
providing an overview of capital and operational costs. These cultivation
systems are the main options currently used for micro-algae
cultivation, although multiple configurations have been proposed
[16,22]. Furthermore, this study determines the overall energy consumption
ratios and costs by taking into account the harvesting and
conversion of micro-algae into bio-energy in the form of heat, fuels
and electricity. The next section will describe the methodology
used, followed by a section assessing key parameters of microalgae
growth. The set-up of the growth model is discussed in
Section 4 of this article. Results of the mass and energy balance,
resulting in the energy consumption ratios, and costs of raceway